Fuchsia's zxtest has a slightly different death test definition, and
this macro makes our death test API work on Fuchsia.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D95648
Standard C allows all standard headers to declare macros for all
their functions. So after possibly including any standard header
like <ctype.h>, it's perfectly normal for any and all of the
functions it declares to be defined as macros. Standard C requires
explicit `#undef` before using that identifier in a way that is not
compatible with function-like macro definitions.
The C standard's rules for this are extended to POSIX as well for
the interfaces it defines, and it's the expected norm for
nonstandard extensions declared by standard C library headers too.
So far the only place this has come up for llvm-libc's code is with
the isascii function in Fuchsia's libc. But other cases can arise
for any standard (or common extension) function names that source
code in llvm-libc is using in nonstandard ways, i.e. as C++
identifiers.
The only correct and robust way to handle the possible inclusion of
standard C library headers when building llvm-libc source code is to
use `#undef` explicitly for each identifier before using it. The
easy and obvious place to do that is in the per-function header.
This requires that all code, such as test code, that might include
any standard C library headers, e.g. via utils/UnitTest/Test.h, make
sure to include those *first* before the per-function header.
This change does that for isascii and its test. But it should be
done uniformly for all the code and documented as a consistent
convention so new implementation files are sure to get this right.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D94642
This moves utils/UnitTest/Test.[h/cpp] to LibcTest.[h/cpp] and adds a
new Test.h that acts as a switcher so that Fuchsia can use the zxtest
backend for running our tests as part of their build.
FuchsiaTest.h is for including fuchsia's zxtest library and anything
else needed to make the tests work under fuchsia (currently just
undefining the isascii macro for the test).
Downstream users, please fix your build instead of reverting.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D94625
Michael Jones